Shower stool



FIG. 1 is a top perspective view of the shower stool;

FIG. 2 is a front view of the shower stool; and,

FIG. 3 is a right side view of the shower stool.

Broken lines shown in the drawings are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a shower stool, as shown and described. 